"A win, a goal and a good game, I have everything to make me satisfied," said Mbappe.

"Now we go to Glasgow to win and to make a good start (in Europe). I've always said that the Champions League is a special competition."

The away side took the lead thanks to a moment of class from world-record signing Neymar.

The Brazilian threaded through a perfect pass with the outside of his foot for Mbappe and Cavani to run onto, with the latter rounding Metz goalkeeper Eiji Kawashima and slotting in his sixth league goal of the season.

Mbappe, 18, continued to show his unselfish side with a wonderful cross for an unmarked Cavani, who was denied by a fantastic Kawashima save.

Metz delivered a sucker-punch eight minutes before the interval, as Mathieu Dossevi's determination down the right-hand side created space for a cross that gave Riviere the simplest of tasks to nod in.

It was the former Monaco striker's first Metz goal since ending his torrid spell at Newcastle United in the close season.

Paris were desperately lucky not to fall behind soon after the restart, as PSG keeper Alphonse Areola's dreadful blunder handed Riviere a golden opportunity, but he somehow contrived to scoop it over the bar.